Japanese Verb Groupings Romaji style
see also: Verb Forms, Counters: Numbers, Time

One way to approach Japanese verbs is to classify them into three major groupings according to the way they are conjugated when spelled with Roman letters. (This classification method does not apply when they are written in the Japanese syllabary.)

These groups are:

Group 1: The u-dropping conjugation
Group 2: The ru-dropping conjugation
Group 3: The irregular conjugation

Knowing which group a verb belongs to enables one to determine the stem of a verb.

Group 1: The u-dropping conjugation

Most of the verbs in Group 1 are easy to recognise. If the ending of the plain (dictionary) form of a verb is anything but -eru or -iru, the verb belongs to this group, with the exception of suru and kuru . As shown below, to determine the stem, simply drop the final -u ending. The masu forms are then made by attaching -imasu/-imasen to the stem.

MEANING to have to take out to enter to hurry to say to need to return to write to buy to wait to paint to think to die to know to fly to take to read

VERB aru dasu 1 hairu * isogu iu iru kaeru * kaku kau matsu nuru omou shinu shiru * tobu toru yomu

STEM ar- dash- hair- isog- i- ir- kear- kak- ka- mach- nur- omo- shin- shir- tob- tor- yom-

MASU FORM arimasu dashimasu hairimasu isogimasu iimasu irimasu kaerimasu kakimasu kaimasu machimasu nurimasu omoimasu shinimasu shirimasu tobimasu torimasu yomimasu

MASEN FORM arimasen dashimasen hairimasen isogimasen iimasen irimasen kearimasen kakimasen kaimasen machimasen nurimasen omoimasen shinimasen shirimasen tobimasen torimasen yomimasen

1 Verbs ending in -su and -tsu have a sh and ch stem.
* Additions to the Group 1 verbs that have -eru or -iru endings.

If the ending of the verb is either -eru or -iru, one must consult a reference source to determine if it belongs to Group 1 or Group 2. A small percentage of verbs ending in -eru and -iru do belong to Group 1. Confusion may arise when words spelled the same way have different meanings. For example, the word kiru, accenting the ki syllable, means "to cut" and belongs to Group 1; its stem is kir-. On the other hand, the kiru that accents the -ru syllable means "to wear" and belongs to Group 2; its stem is ki-. Similarly, the word kaeru, accenting the ka syllable, means "to return" and belongs to Group 1; its stem is kaer-. Whereas the kaeru that accents the e syllable means "to change" and belongs to Group 2; its stem is kae-. Sometimes there are no pronunciation differences differences, as with iru. While the word iru meaning "to need" belongs to Group 1 (stem ir-), iru meaning "to exist" belongs to Group 2 (stem i-). Both are pronounced the same.

Group 2: The RU-dropping conjugation

Most verbs ending in -eru or -iru belong to this group. The stem is formed by dropping the -ru ending.

MEANING to raise, give to be able to be to think to see to eat

VERB ageru dekiru iru kangaeru miru taberu

STEM age- deki- i- kangae- mi- tabe-

MASU FORM agemasu dekimasu imasu kangaemasu mimasu tabemasu

MASEN FORM agemasen dekimasen imasen kangaemasen mimasen tabemasen

Group 3: The irregular conjugation

This group has only two verbs, kuru "to come" and suru "to do".

MEANING to come to do

VERB kuru suru

STEM ku-,ki- shi-

MASU FORM kimasu shimasu

MASEN FORM kimasen shimasen

Verb stem + adjuncts

Many adjuncts are attached to the verb stem to alter the verb's original meaning.

1. isogi-nasai
   Hurry up.
   
   
2. ame ga furi-sou desu
   It looks like it will rain.
   
   
3. watashi wa benkyou shi-tai desu. shigoto wa shi-takunai desu
   I want to study. I don't want to work.